Keyboard for calculating machines



Oct. 22, 1929. A. A. HoRToN KEYBOARD FOR CALCULATING MACHINES Filed Aug. 6, 1926 Patented Oct. 22, 1929 UNITED STATES PATENT oI-Flcs ALLEN A. HORTON, OF PLYMOUTH, MICHIGAN, ASSIGNOR TO .BURROUGHS ADDING MACHINE COMPANY, OF DETROIT, MICHIGAN, A CORPORATION OF MICHIGAN KEYBOARD FOR CALGULATING MACHINES."

Application filed August 6,

The invention relates to a keyboard for calculating machines.

It relates particularly to the mechanism tor releasing erroneously depressed keys by r means ot' an error key.

A mechanism for this purpose is shown in my (zo-pending application7 Seria-l No 84,616 tiled January 29, 1926, of which the present application is a continuation in part. An improved form of said mechanism is shown in the present application, such improvement consisting mainly in an arrangement for making the error key easiery to operate. The present application relates to the broad in vention represented by the form shown in my prior application as'well as the present form to which this application is particularly directed.,

'The general object of the invention is to provide an improved key releasing mechanism.

A more particular object is to provide a releasing mechanism operated by an error key which may be easily manipulated.

Other objects and advantages ot' the invention will hereinafter appear.

An embodiment of the invention is illustrated in the accompanying drawings in which:

Fig. 1 is a side elevation of a keyboard showing the error key and associated parts in normal position.

Fig. 2 is a fragmentary view similar to Fig. l showing one ot the amount keys dev pressed and the error key slightly depressed.

Fig. 3 is a fragmentary view similar to Fig. 1 showing the position of the parts when the error key is 'fully depressed.

Fig. 4 is a section on the line 4-4 of Fig. 1.

Fig. 5 is a perspective View of the controlling or releasing mechanism operated by the error key.

The invention is shown in connection with a keyboard of the type disclosed in my copending application, Serial No. 84,616, tiled sion a coil sprin 192e. serial Nofiezsio.

January 29, 1926. An understanding of all the details ot said keyboard is not necessary for an understanding of the present invention which is not necessarily limited tothe keyboard of said application.

r1`he keyboard comprises a trame having a top plate 2O and a bottom plate 21 joined by vertical plates 22. Two of the vertical plates have downwardly extending projections 23 at theirl rear ends for connecting the keyboard to a calculating machine, and similar projections 24 (Fig. 4) extend downwardly at the front end where they support a safety control unit that Will be later explained.

A series of banks of amount keys and a series of control keys comprising an error key E, a repeat key R, and non-add key N-A, a total key T and a sub-total key S-T are mounted in the keyboard, each of said keys having a flat stem extending through the top and bot-tom plates. lVhen'- ever any of the keys are depressed they teng 25 ior that bank ot' keys which spring tends to urge the keys upivardly to undepress'ed position. extend through holes in the key stems below y' the bottom plate 21 ot the keyboard and through eyes 26 struck out from the bottom plate, the ends of the springs being anhored by rods 27 and 28 as illustrated in t1ig. 1.

The stem oit each amount key is provided with a slot tor the reception ot a. positioning plate 30 and with a similar slot 31 (Fig. 1) parallel to the first for receiving a latching plate 32, the latter being provided with projections' 33 having noses 34. In the case ot the control keys these parallel slots are merged into one wide slot as shown in Fig. 4. Each ot the key stems except the error key has a slot above the slot for the latching plate for receiving the adjacent nose 34 on the latch plate whenever the key is depressed as illustrated in Fig. 2. The latch plates 82 are normally urged forwardly by These sirinvs springs 36 at the rear of the keyboard, which are connected at one end to the stationary vertical positioning plates 30 and their other ends to the latch plates. `Whenever a key is depressed the portion of the key stem between the top and bottom slots engages the beveled face of the nose 34 of the adjacent projection on the latch plate 32 and pushes the latch rearwardly. Then the key reaches its depressed position, excepting` the error key which is not locked down, the upper slot in its stem is opposite the nose and the nose is then free to move into the slot which it does under the action of its spring` 36. This lat-ches the key in depressed position.

The forward ends 40 of the latch plates are hook shaped and their hooked ends engage over lateral projections 41 on the upper end of pivoted zero stop members 42. IThese members are pivoted to a shaft 43 carried by -the downwardly extending projections 24 011 the' vertical frame plates 22. The lower ends of the zero stop members are bifurcated at 44 to provide a forward portion 45 in front of a control rod 46 and a rear port-ion 47 to the rear of said rod, the bifurcation being wider than the diameter of the rod so as to allow relative movement between the rod and the zero stop members. This control rod serves to control a safety device explained in det-ail in my (zo-pending application. It will be observed that the connection is such that whenever one of the latch plates 32 is moved its respective zero stop member 42 fnoves clockwise with it, the clockwise movement of the zero stop being permitted' by rod 46 owing to the wide bifurcation44, and vice versa, when the Zero stop members are moved the latch plates are moved by them.

At tlre end of the return stroke of the machine the latch plates are allmoved rearwardly to, release the depressed keys by means of a reciprocating plate 201 having an upper shoulder 207 and a lower shoulder 208 for engaging roller 49 on the control rod 46 to push it forwardly to therebyrock the zero stops clockwise and move the latch plates to the rear. ciprocating plate 201 operates to release the latch plates is fully described in' my previously mentioned copending application to which reference is made for details, it being suiicient toknow for the purposes of this application that on the forward stroke of the machine the slide 201 is tilted upwardly to position the shoulder 208 in the rear of roller 49 and that upon the return stroke the slide 201 moves forward to .move the cont-rol rod 46 and zero stops 42 sufficiently to push all the latch plates rearwardly far enough to release any keys that have been depressed.

In order that depression of the error key shall release all other keys that have been depressed, it is desirable that all the latch plates be moved to the rear by the error The manner in which this rekey. In my prior application this was effected by an arrangement by means of which depression of the error key moved the latch plate for the bank of control keys farther to the rear than was the case by depression of any of the other keys with the result that the zero stop member for said bank was moved clockwise far enough to engage the control rod 46 and move it forward to move all the other latch plates to the rear sufficiently to release their keys. In the present invention the error key moves the rod 46 without going through t-he latch plate, novel connections being provided as follows:

A. member 50 is pivoted to the shaft 43 by means of a hook shaped projection 51. A downwardly extending portion of this member is bifurcated at 52 to straddle the control rod 46 and this portion also carries a stud 53 to which is connected one end of a spring 54 that normally urges the member counterclockwise. The member 50 also has a rearward portion 55 adapted to contact the underside of the lower plate 21 of the keyboard. Also pivoted on the shaft 43 is a bell crank member 60 having a rearwardly extending arm provided with a nose 61 adaptedl to engage the underside of the frame plate 21. The downwardly projecting' arm of the bell crank extends'into a slot in the member 50 formed between the bodyof said member 50 and a lug 56 extending laterally from it and forming an abutment projection. Pivoted at 62 on the bell crank 60 is a lever 70 having a lateral projection 71 extending between the projections or jaws 63 and 64 on the rear arm of the bell crank. The thickness of this lateral projection 71 is less than the space between the jaws 63 and 64 so that the lever 70 has a limited movement on its pivot. The lateral projection 71 also extends under the stem of the error key as shown in Fig. 4 and it has an upwardly extending projection 72 extending into a slot in said key stem. vThe forward end ofthe pivot lever has an abutment portion or foot 73 which may be positioned in front of the lateral lug 56 on the member 50 but the lever is normally urged counter-clockwise by a spring 7 4 to keep the abutment. out of the path of the lug.

The operation of theseparts is as follows:

Normally the parts occupy the position illustrated in Fig'. 1 where the error key is in its normal position and the abutment 73 is belpw the path of the laterall projection 56 on the member 50. The control rod 46 with its associated parts is thus free to move rearwardly as it must do under some circumstances in operation ofthe machine, as for example, when it moves rearwardly to permit the 1keys to be locked and to move the zero stops to arresting position. Accordingly, the releasing mechanism operated by the error key does not interfere with the ordinary operation of the machine.

When the error key is depressed its stem first moves the parts to the position illustrated in Fig. 2, that is, the lever arm is moved on its pivot to move the abutment 73 up behind the lug 56 on the member 50. Movement of t-he lever 70 is limited by the engagement of its lug 71 with the lower jaw 63 of the bell crank 6() and hence further downward movement of the error key stem moves the bell crank 60 clockwise and at the same time the member 50 is rocked clockwise by the engagement of the abutment 7 3 with the lug 56. Since the member 50 is astride the control rod 46, the latter is moved forwardly and the parts are proportioned so that this movement is ample to move the zero stops 42 sufficient to move all the latch plates 32 far enough to the rear to release any keys that may have been depressed.

When the error key is released the spring 74 returns the bell crank 6() and the lever arm 7 0 to normal position and also raises the error key to undepressed position, said key not being provided with any latching means for holding it depressed. The member 50 and the control rod are returned to normal by the spring 54. The return movement of the bell crank 60 is limited by the engagement of its nose 6l with the underside of plate 21.. The rear projection 55 of the member 5() limits the movement of that member when the control rod 47 is moved rearwardly during operation of the machine.

By means of this construction the error key may act with a long leverage t-o move the control rod 46 forward to release the latches which enables the key to be easily depressed. The releasing mechanism is coordinated with the other parts of the machine so as to function without interfering with their normal action.

It is to be understood that changes may be made in the construction illustrated without departing from the spirit and scope of the invention as defined by the appended claims.

I claim:

1. In combination, in a calculating machine keyboard, banks of depressible keys, a latch plate for each bank for latching the keys of its bank in depressed position, -control means for all of said latch plates adapted to be moved during operation of the machine, an error key having a key stem, and normally disabled connections between said error key stem and said control means, said connections being enabled by initial depression of said error key whereby further depression of said error key will move the control means to move the latch plates to release depressed keys.

, 2. In combination, in a calculating machine keyboard, banks of de ressible keys, a latch plate for each bank or latching the keys of its bank in depressed position, control means for all said latch plates adapted to be moved during operation of the machine, an

to move the latch plates to release depressed c keys.

3. In combination, in a calculating ma chine keyboard, banks of depressible keys, a latch plate foreach bank for latchng the keys of its bank in depressed position, a control means for said latch plates including an abutment projection having a liXed path of movement during operation of the machine, an error key having a. key stem, connections between said error key stem and said abutment projection, and means for urging said connections out of the path of said abutment projection, said connections being movable by initial depression of said error keyI into the path of said abutment whereby further depression ot' said key will move the control means to move the latch plates to release depressed keys.

4. In combination, in a calculating machine keyboard, banks of depressible keys, a slidable latch plate for each bank for latching the keys of its bank in depressed position, members pivoted at the front of the keyboard and connected to said latch plate, a control rod for controlling said pivoted members, an error key, and a pivoted lever mechanism extending between said error key and said controllrod whereby depression of said key will move the control rod to move the pivoted members to release depressed keys.

5. In combination, in a calculating machine keyboard, banks of depressible keys, a latch plate for each bank for latching the keys of its bank in depressed position, a pivoted member connected to each of the latch plates at the front of the keyboard, a control rod for controlling said pivoted members, an error key, a lever pivoted at the front oi the keyboard having an extension positioned adjacent the error key and another' extension adjacent said control rod, said lever being normally disconnected from said control rod, and means operated by initial depression of said error key for connecting said lever to said control rod whereby further depression of said error key will move said control rod to move said pivoted members to move the latches to release depressed keys.

6. In combination, in a calculating machine keyboard, banks of depressible keys, a latch plate for each bank for latching the keys of its bank in depressed position, a pivoted member connected to each latch, a control rod forcontrolling all of said pivoted members, an abutment carried by said control rod, an error key, a lever pivoted near the front of the keyboard and having an eX- tension adjacent the key stem, said lever having another extension positioned adjacent said abutment, a second lever pivoted to the first and positioned for operation by said error key whereby, upon initial depression of the error key, said second lever will be moved to operatively connect said irst lever to said abutment to cause further depression of said error key to move the control rod to move said pivoted members to move the latches to release depressed keys.

7. rlhe combination in an accounting machine keyboard of banks of depressible keys, latch plates for latching said keys in depassed position, members pivotcd at the forward end of the keyboard and connected to said latch plates, a swingable control rod cooperating with said members and serving to move 'an abutment projection, an error key, and connections controlled by the error key for engaging said abutment projection, said connections being normally out of the path of said abutment projection but being movable by said error key to a position to engage said projection to move the control rod to move the latch plates to release depressed keys.

8. ll`he combination in a calculating machine keyboard of banks of depressible keys, latch plates for latching said keys in depressed position, members pivoted to a shaft at the forward end ofthe keyboard and connected to said latch plates, a swingable control rod cooperating with said members, a member pivoted to said shaft and connected to said control rod, said member having an abutment projection, a second member pivoted to said shaft, a third member pivoted to said second member and having a limited movement relative thereto, and an error key positioned to engage the third member to move it to cause it to engage said abutment projection to thereby move said control rod and latches to release depressed keys.

9. The combination in arcalculating machine keyboard of banks of depressible keys, latch plates for latching the keys in depressed position, a shaft at the forward end of the keyboard, members pivotcd to said shaft and connected to the latches. the lower ends of said members being bifurcat'ed, a control rod positioned in the bifurcated ends of said members, a member pivoted to said shaft and straddling said control rod, means for normally urging said member in a counter-clockwise direction,'said member being provided with an abutment projection, a second member pivoted to said shaft vand extending rearwardly, the rear end of said second member having a pair of separatedj aWs, a third meinber pivoted to the second member and having a lateral projection extending between said jaws, said third member having an abutment foot adapted to engage said abutment projection, means for normally urging said name. l

ALLEN A. HORTON. 

